


Somebody Holds the Key

by PorcupineGirl



Category: Supernatural
Genre: Castiel's Grace, Love Confessions, M/M, Mark of Cain, Post-Episode: s10e18 Book of the Damned
Language: English
Status: Completed
Published: 2015-04-19
Updated: 2015-04-19
Packaged: 2018-03-24 19:48:33
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,136
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3782188
Author URL: https://archiveofourown.org/users/PorcupineGirl/pseuds/PorcupineGirl
Summary: <blockquote class="userstuff">
              <p><i>Power radiates off of Castiel in a way that Dean hasn't seen firsthand in a while, a way that forcibly reminds him of a long-ago barn. When Cas looks up, the single-minded determination in his face recalls that angel, the one that hasn't truly existed in years.</i><br/> <br/> <i>"The Mark. I can save you."</i></p><p>We all know how this story ends.</p>
            </blockquote>





	Somebody Holds the Key

**Author's Note:**

> Not an episode coda so much as a projection to the end of S10 given the events of 10x18 (well, things that have been building for a long time now but I think were crystalized by that episode). Title is from Eric Clapton's _Can't Find My Way Home_

By the time Dean steps into the warehouse, it's over.  
  
There are two things at Castiel's feet: The demon tablet, shattered, and Metatron's dead body.  
  
Power radiates off of Castiel in a way that Dean hasn't seen firsthand in a while, a way that forcibly reminds him of a long-ago barn. When Cas looks up, the single-minded determination in his face recalls that angel, the one that hasn't truly existed in years. One Dean doesn't miss much, if he's being honest. The thought that Cas might be reverting back to who he once was makes Dean's heart race. He's lost Sam already, for the moment at least; he can't lose Cas, too. He just _can't._  
  
"I can fix it," Castiel startles Dean out of his reverie, crossing over to him in long strides. "I can fix you, Dean. The Mark. I can save you."  
  
It takes Dean's mind a second to catch up.  
  
"You - the Mark? You can remove it? How?"  
  
Cas's steely gaze falters. He looks away.  
  
"Just let me do it, Dean."  
  
"Whoa whoa whoa, I don't like the sound of that." Dean puts a hand on Castiel's shoulder. "What aren't you telling me, man? What's the price?"  
  
"There is no price to you," Cas says, and then he looks Dean in the eye again. "And no price that I am not fully willing to pay."  
  
"Cas!" Dean's hand tightens. "You saw what happened to Sam. I can't let you go off the rails, too. If you know what the risk is, you tell me and I'll decide if it's worth it."  
  
Castiel narrows his eyes, his gaze penetrating Dean. " _You_ , of all people, Dean, are not an accurate judge of your own worth."  
  
Dean's insides squirm, but he doesn't let it show. He can tell this is not a line of reasoning that will work with Cas, hasn't been since the day they met.  
  
"Whatever it is, how do you even know it'll work? Because Metatron told you so? That dick was probably lying, you know that." It's not deflection, it's the truth. Okay, and maybe a little deflection, but that doesn't make it less true.  
  
"He didn't tell me; I looked into his head and pulled the information out. He can't hide it from me as a human. I am one hundred percent certain that this will work. Permanently."  
  
Dean tamps down on the tendril of hope blooming in his stomach. If this were something he'd agree to, Cas would have already told him the details. If Cas doesn't want him to know, then it can't be worth it. Just like Sam's attempt wasn't worth his sacrifice. But an angel saying they're one hundred percent certain... is tempting. Too tempting.  
  
"I need your permission, Dean."  
  
Dean nearly jumps, startled out of his thoughts. Then he realizes the implications of Cas's words.  
  
"Why, do you need to possess me?" Maybe this isn't so bad, maybe Cas possesses him, does some internal work on him like Gadreel did on Sam... And Dean trusts Cas, knows it wouldn't be like _that_.  
  
Cas's eyes fall away again. _Not good._ "Not exactly, no. In any case, I could not possess you even with permission; you are not a suitable vessel for me. But my grace cannot enter your body at all without your permission, and that is what is required."  
  
Dean finally pulls back the hand on Cas's shoulder, crossing his arms. He can see where this is going, and it's a place that gets a big _fuck no_ from him.  
  
"So your grace has to enter my body, but it's _just_ your grace. Not all of you possessing me. You'll be separated from your grace. Again. Great plan, Cas. So what happens once your grace is done playing cleanup crew to the Mark? It brings the Mark back with it, and now you're stuck with it?" He almost hopes that's what Cas is suggesting, because the other alternative...  
  
"No. This does not involve me taking on the Mark in any way. The Mark will be entirely obliterated."  
  
Dean grunts, running a hand through his hair. "And lemme guess - your grace goes with it."  
  
Castiel's eyes meet his again, and the angel looks angry enough that Dean nearly expects him to start glowing. His nostrils flare and his fists clench, but his angelic wrath does not make an appearance.  
  
"I told you, it is a price that I am fully willing to pay. That is my choice, Dean. One that I am making of my _own free will._ Do not deny me that."  
  
It's a low blow, using those words. Was free will a gift that Dean gave him, or a curse that he hung around the angel's neck? Time to change tactics again.  
  
"Don't you have Metatron's grace? Nobody needs that anymore, use it to do the dirty work."  
  
"It has to be mine, Dean. No other angel's will work."  
  
"Why?" Dean is frustrated and confused, but not truly surprised. Of _course_ it has to be Cas's, it wouldn't be Dean's life otherwise. "That's the dumbest thing I've ever heard. There's no fucking way the demon tablet says 'the key to destroying the Mark of Cain is Castiel's grace.'"  
  
Dean is surprised when Castiel's gaze falls to the side yet again.  
  
"It does not mention me by name, no." For all that he was amped up with stubbornness and mojo a minute ago, his voice is suddenly quiet. "But I am the only angel who fulfills the requirements. Of that I am... quite certain."  
  
"How do you know that?" Dean's voice is soft too, taking his cue from Cas. "Tell me why it has to be you or no deal, Cas. I need to know all the details of whatever we're getting into here."  
  
Castiel looks up at him again, and Dean can see the weight of every one of his millennia in those eyes. He doesn't speak for a long moment.  
  
"Only my grace will work because I am the only angel who is in love with you, Dean." His voice is remarkably steady for what he just said. "That is what the tablet says. An angel must fall in love with the bearer of the Mark, and only then will that angel's grace have the power to destroy it. I could have destroyed it all along, if only we'd known."  
  
Dean doesn't hear much after the first sentence, though. His mind is a tangle of contradictions: this is what he wants to hear, has wanted for a long time, but also what he fears most. He has always known it to be true yet doubts it sincerely. He wants to embrace it and reject it with equal fervor.  
  
"You don't - Cas, come on. You're new to this emotion thing. Maybe you think you're in - in love with me, but you're not, man. You can't be. You can't be." He can't be. He's seen the worst that Dean is capable of, so much worse than most people. _Humans_ don't fall in love with that, let alone angels.  
  
Castiel tilts his head, but holds Dean's gaze. "On the contrary, Dean. I have proof, at least that my feelings qualify by the tablets' standards. It is also the reason that Metatron needed my grace specifically to close heaven. He killed several angels, including Naomi, to get to me, and did not take their grace. Because the last ingredient in his spell was the grace of an angel in love with a human. Apparently my Father made that particular act so powerful because he... he did not believe it to be possible." Dean snorts; Cas's talent for fucking up God's plan knows no bounds. It's the one thing that could convince Dean that Castiel might actually feel this way.  
  
This time it's Cas's turn to put a hand on Dean's shoulder. "This will work."  
  
Dean's hand goes automatically to cover Castiel's. His thumb rubs absently over Cas's fingers while he tries to navigate the weight of what just happened.  
  
"Okay," he hears himself croak out. He immediately wants to take it back, but he can't. Cas just put himself out there in a way Dean has never, could never do. How can Dean possibly refuse him anything right now? "You're right, Cas. It's your choice. Whatever you decide to do, I'm with you."  
  
Instead of answering, Cas's other hand shoots out, cradling Dean's jaw and carefully prying his mouth open. Then Cas's mouth seals itself over his, and Dean's eyes fall closed on reflex. It's an odd kiss, until he realizes that it isn't a kiss at all. Cas's mouth is holding his open, but there is no tongue involved. Before Dean can even wonder what is happening, though, a bright light surrounds them. The sensation that passes through his mouth and into him is indescribable - searing and icy at once, a surge of pure power that both soothes and electrifies. He can actually feel it envelop the Mark - not the scar on his arm, but the thing that has attached itself to his soul and clung there for nearly two years now.  
  
He doesn't know how Castiel knows exactly when to pull back, but apparently he does. As soon as their mouths part, the blue light of the grace flows out of Dean's, carrying whatever remains of the Mark with it. Instead of flowing back to Cas, or up to heaven, or even into a vial, though, it simply dissipates almost as soon as it's out. They watch the last of Castiel's grace disappear before their eyes.  
  
Castiel slumps against him, forehead on Dean's shoulder. Dean doesn't have to check his arm to know that the Mark is gone, though he does anyhow. He feels clean and light and _normal_ in a way he hasn't since he met Cain, a way he'd forgotten was possible.  
  
He slides his arms around Cas and carefully lowers them to the ground. One hand cards through dark hair, and he finds himself kissing Castiel's head, over and over and over again.  
  
"I got you. I got you," he murmurs into the hair. And it's not what he means, not what he wants to say, not what he _should_ say at all. But it's all he can say, again and again.  
  
_No,_ he thinks, _Fuck that. Cas deserves better, Winchester, and it's your responsibility to put aside whatever mountain of bullshit you're hiding behind and give it to him._  
  
"I love you," he finally whispers. Saying it once breaks the dam open, and Dean knows it will never be hard to say again. "I love you. God, I love you, Cas."  
  
Cas's arms come up to wind around his waist, and he can feel how weak they are. Cas needs rest, and food, and... and, god, what else can Dean give him? He'll figure it out. He lifts his face up out of Cas's hair and speaks at a normal volume.  
  
"I'll make this up to you, Cas." His voice is shaking. "I swear, I will spend the rest of my life making it up to you."  
  
"No," Castiel's voice is muffled by Dean's shoulder, but after a second he manages to raise his head enough to meet Dean's eyes once again. "We're not keeping score, Dean. I don't want you to make it up to me or owe me something for it, or any of the other foolish things that I know you think you need to do."  
  
Dean nods, not believing himself for a minute but knowing that he'll at least try to ignore the impulse.  
  
"Let's get you home." His voice is gentle, his hand coming up to rest on Cas's cheek. Cas closes his eyes and leans into the touch, and Dean melts. He's still not sure he can handle this, handle actually having this, but he'll sure as hell try. He strokes Cas's lips with his thumb. "We get you home, you can rest up, we'll get you all sorted out. Couple days, we'll start looking for Sam."  
  
Before he can chicken out, he leans forward and presses a soft kiss to Cas's mouth. Cas jerks back, his eyes flying open.  
"Dean, don't feel like you have to - you don't owe me -"  
  
Dean surges forward, interrupting him with a harder, more insistent kiss.  
  
"I know, I know." He manages to work a few words in between kisses. "Don't owe you shit." He licks his way into Cas's mouth and moans lightly as their tongues brush. "Bein' selfish here, Cas." They cling to each other, kneeling there on the floor. When Dean finally pulls back again, they're both breathing hard.  
  
"Let's go home, Cas."  
  
"Home," Cas murmurs. His gaze falls somewhere in the vicinity of Dean's shoulder, eyes unfocused. He finally raises them to meet Dean's. "Yes. Home."

**Author's Note:**

> [My tumblr]()


End file.
